In French, these are called Sous-Marin Nucléaire Lanceur d'Engins de Nouvelle Génération (English: "Next Generation Device-Launching Nuclear Submarine"), abbreviated as SNLE-NG. They have replaced all of the Redoutable-class boats, with the last of those six boats being decommissioned in 2008. These submarines carry 16 submarine-launched ballistic missile launching tubes apiece.

This class reportedly produces approximately 1/1000 of the detectable noise of the Redoutable-class boats (submarines), and they are ten times more sensitive in detecting other submarines.[4] Initially armed with the M45 missile, they are designed to carry the new M51 missile, which entered active service in 2010. As of October 2010[update], an M51 has been test-fired from one of these submarines across the Atlantic Ocean from near France to the west, and is equipped on Terrible.

The French Navy's goal is to operate a force of four ballistic missile submarines (comparable with the Royal Navy's Vanguard-class submarines), of which two are expected to be on patrol at any given time.

On 3 February or 4 February 2009, Le Triomphantcollided with the Royal Navy submarine HMS Vanguard; the Royal Navy boat suffered minor scrapes and scratches.[6]Le Triomphant was reported to have proceeded to Brest under her own power, submerged, but with extensive damage to her sonar dome.[7]